The present invention relates to the high-speed printing industry, and more particularly, to a system and method for merging variable data and images into a template image defined by a page description language file in a high speed printing environment.
Application programs, such as wordprocessors, illustrators, and computer aided design systems are software packages used to create a document (text and graphics) on a computer screen and to simultaneously generate a page description language ("PDL") specification, which is to be transferred to the printer, or to any other type of raster device or output device for creating a hard copy or copies of the document. Alternatively a PDL specification can be generated by a programmer without the assistance of an application program.
The printer executes the PDL specification to generate a bitmap of the document, or a raster-data representation of a document, and eventually transfers the bitmap or raster-data to a physical medium such as paper. A typical PDL language, such as PostScript (a registered trademark of Adobe Corporation) defines a page of the document as containing a number of data areas, where each data area contains either graphic or alpha-numeric data. Each data area is defined by a "graphic state," which is a collection of parameters or attributes for controlling the representation and appearance of text and graphics. For example, the graphic state can include a set of text attributes such as scale factor, type font, etc. In postscript an example of a PDL command used to build a graphic state can be:
20 rotate /Times-Roman findfont 14 scalefont setfont PA1 0 0 moveto and (ABC) show
Examples of PDL commands used to define the graphic or alpha-numeric data that is displayed in the data area include:
The entire group of PDL commands used to define a document is hereinafter referred to as the "PDL specification." Furthermore, the entire graphic state, or any particular attribute or combination of attributes included in a graphic state, or any similar attribute contained in a PDL specification for defining or controlling the representation, location and/or appearance of text and graphics in a final bitmap or raster image is hereinafter referred to as "graphic attributes."
In variable data printing each printed document shares a common template and there is at least one area in the template that changes for each printing of the template. Typical PDL languages are not designed for high-speed variable data printing because, with PDL languages and interpreters, even if a single item of data in the document changes, an entirely new PDL specification must be created and interpreted. For example, if 100,000 copies of a mass mailing advertisement were to be printed (i.e., each copy of which is identical except for the mailing address) it is typically necessary to generate a new PDL specification for each copy to be printed. Hence, to generate 100,000 advertisements, it would be necessary to generate 100,000 PDL specifications, even though each advertisement is virtually the same except for the variable data area. The processing time required to interpret and render 100,000 PDL specifications is enormous, significantly slowing the entire printing system.
Furthermore, typical PDL languages do not include the capability of rapidly merging variable images or bitmaps (such as company logos, coupons, charts, and the like) along with variable text data into the template bitmaps. Accordingly, there is a need for a high-speed printing operation having the ability to merge variable data (which includes variable text data and bitmap images) into a template defined by a PDL specification.